The Washington area (and beyond) offers plenty of triathlons for beginners and seasoned veterans alike. Here is a list of triathlons in D.C., Maryland and Virginia through the end of June. We’ll tackle the second half of the year next week. Be warned, don’t delay in signing up: Several major local triathlons are already full, although some charity slots are still available. March 6: Tri to Help Maryland, Reisterstown. This is an indoor mini-triathlon, with a 10-minute swim, 30-minute bike on a stationary bike and 20-minute run on a treadmill. It’s a fundraiser for epilepsy research. Info: tritohelp.org.